US says no radiation released in steam leak at nuclear site

Originally published October 26, 2018 at 9:05 am
Updated October 29, 2018 at 11:22 pm

An Energy Department spokesman said there were no signs of radioactive contamination after steam from a tunnel forced hundreds of workers to take cover at the Hanford Nuclear Reservation on Friday. (AP Photo / Manuel Valdes)

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SPOKANE, Wash. (AP) — No airborne radiation was detected after steam escaped Friday from a tunnel containing radioactive waste at a former nuclear weapons production site in Washington state, U.S. officials said, the second problem with aging tunnels at the Hanford Nuclear Reservation in a year.

Workers who had been ordered to stay inside buildings were released about five hours later, the U.S. Department of Energy said. There were no reports of injuries.

The agency said cameras revealed that the steam resulted from the drying of a cement-like grout that was recently pumped into the 54-year-old tunnel to stabilize it. The tunnel stores nuclear waste in railroad cars left over from the Cold War, and it’s in danger of collapsing.

“The curing process generates heat and moisture,” the agency said in a press release. “When the warm moist air left the tunnel and interacted with the cool early morning atmosphere, steam was visible.”

Most of the plutonium for the nation’s nuclear arsenal was created at Hanford, located along the Columbia River in eastern Washington. About 9,000 workers on the site are involved in cleaning up the nation’s largest collection of radioactive waste left over from the production of nuclear weapons.

A different tunnel at Hanford partially collapsed last year and workers were ordered to stay inside for several hours. There was no airborne release of radiation, and no workers were injured in that incident. Work to fill that tunnel with grout was completed last November.